I had a similar entity in a game I am currently working on. While mine don't explode and you may need help in that aspect, here is the script for my entity:
;Artificial Intelligence Script
;Header
desc = Hoverbot
;Triggers
:state=0:floatrate=20
:state=0:spinrate=20
:plrdistwithin=50:plraddhealth=-2
;End of Script
What you would need to do is get rid of spinning ":state=0:spinrate=20" unless you want your entity to spin, and then change the floatrate (bounce or float, depending on value) to 100, or until you get the desired bouncing effect. As of now, I don't know how you could go about the ball exploding, however, when the player comes into contact with the ball or what have you, the player's health will decrease by 2 points.
If you really want the entity to explode, you may have to animate that, it might be impossible with scripting. Once you have the ball animated to explode, then you could have that animation scripted at the frame the explosion occurs on.
Actually, I browse around the boards just to critique stories to make them more original, it seems that many are doing the "Shoot everyone in your sight"
-Light Samus
